This invention relates generally to aquariums and more particularly to a method and device for maintaining a healthy environment for fish within the aquarium, by removing undesirable materials from the aquarium water.
Undesirable material is being generated constantly within an aquarium. Fish ingest food and eliminate solid and chemical wastes. Uneaten food also leads to solid waste. That solid waste can also be broken down by bacteria within the tank to form other secondary wastes. These wastes can encourage the growth of algae or other undesirable life forms and stress fish in the aquarium. Accordingly, it is desirable to remove both solid and chemical wastes from an aquarium in order to provide a healthy environment and reduce stress on fish within the aquarium.
A common aquarium filter employs carbon particles for removing organic waste from the aquarium water and a fibrous pad or wad to trap solid waste. The carbon and fibers are commonly located in a small tank which hangs from the side of the aquarium. A pump is used to draw water from the aquarium into the conventional filter which then flows from the filter back to the aquarium. Changing the charcoal and fiber is inconvenient and the filter has little aesthetic value. Furthermore, the carbon/fiber filter system can be unable to minimize certain wastes that can put stress on fish in the aquarium.
Other conventional filters draw aquarium water into the gravel at the bottom of the aquarium which then flows out through carbon particle cartridges. Solid matter becomes trapped in the gravel, where it can decompose biologically. Some of the biological decomposition leads to undesirable chemical byproducts which can stress the fish. The carbon cartridges are employed to remove organic material from the aquarium water. Such filters leave unsightly debris at the aquarium bottom and are ineffective for removing certain chemical wastes.
Over the years, various attempts have been made to overcome functional and aesthetic drawbacks in conventional filters. U.S. Pat. No. 3,135,238 describes a filter tank mounted on the side of an aquarium. Water is drawn from the aquarium, to the tank, down through a filtering medium such as sand or glass wool for catching waste and sediment, then back to the aquarium by passing up through the gravel for the purpose of additional filtration of the finer particles of waste and foreign matter.
U.S. Pat. No. 4,002,566 describes an external tank that receives waste from the aquarium. The water passes through a coarse filter material in the tank, then back through the bottom of the aquarium and up through the gravel. Gases, such as ammonia, derived from fish waste and uneaten food is merely permitted to evaporate from the surface of the aquarium water.
U.S. Pat. No. 4,606,821 describes a multi-layer filter in which water flows into the top of the filter, down through multiple layers of filtering media, then up through the bottom of the aquarium. U.S. Pat. No. 4,863,594 also describes a filtration method in which water flows up through the gravel to prevent uneaten food and waste from accumulating therein. U.S. Pat. No. 5,062,951 describes an in-tank pump, which draws in water and forces it up and out through the gravel on the aquarium floor. U.S. Pat. No. 5,172,650 describes an aquarium filter in which sediments are collected separately so that they can be removed without interfering with operation of the filter. The contents of U.S. Pat. Nos. 3,135,238, 4,002,566, 4,606,821, 4,863,594, 5,062,951 and 5,172,650 are incorporated herein by reference.
Although these patents present various ways of attempting to maintaining a healthy environment in an aquarium, they have shortcomings. None present a fully satisfactory method and filter for eliminating waste from the aquarium water. For example, while some of these discusses the use of bacteria colonies in gravel bed, for providing biological filtration, such filtration has not proved to be fully effective for removing undesirable chemicals from the water. Furthermore, the bacteria grow in a generally unrestrained and uncontrolled manner and can be detrimental to the aquarium environment. Also, the accumulation of debris at the bottom of the aquarium is undesirable, unhealthy and unsightly. Finally, many of these filters require flow rates that unduly stress certain types of fish in order to provide effective filtration. Accordingly, it is desirable to provide an improved aquarium filter which overcomes the drawbacks in the prior art.